The present invention is directed to circuit interrupters, and more particularly to circuit interrupter operating mechanisms.
Circuit interrupter operating mechanisms are used to manually control the opening and closing of movable contact structures within circuit interrupters. Additionally, these operating mechanisms in response to a trip signal, for example, from an actuator device, will rapidly open the movable contact structure and interrupt the circuit. To transfer the forces (e.g., to manually control the contact structure or to rapidly trip the structure with an actuator), operating mechanisms employ powerful springs and linkage arrangements. The spring energy provides a high output force to the separable contacts.
Commonly, multiple contacts, each disposed within a cassette, are arranged within a circuit breaker system for protection of individual phases of current. The operating mechanism is positioned over one of the cassettes and generally connected to all of the cassettes in the system. Because of the close position between each of the cassettes, and between each cassette and the operating mechanism, the space available for movable components is minimal. It would be desirable to maximize the available space to reduce friction between movable components within the operating mechanism.
Furthermore, circuit breaker arrangements are provided for 3-pole and 4-pole devices. Inherently, the position of a circuit breaker operating mechanism relative to a 4-pole device is asymmetrical. Therefore, it will be desirable to provide a circuit breaker operating mechanism that maximizes the output force to the poles of the circuit breaker system while minimizing the lost forces due to, for example, friction.
An operating mechanism for controlling and tripping a separable contact structure arranged in a protected circuit is provided by the present invention. The separable contact structure is movable between a first and second position. The first position permits current to flow through the protected circuit and the second position prohibits current from flowing through the circuit. The mechanism includes a frame, a drive member pivotally coupled to the frame, a spring pivotally connecting the drive member to a drive connector, an upper link pivotally seated on the drive connector, a lower link member pivotally coupled to the drive connector, a crank member pivotally coupled to the lower link member for interfacing the separable contact structure, and a cradle member pivotally secured to the frame and pivotally securing the upper link. The cradle member is configured for being releasably engaged by a latch assembly, which is displaced upon occurrence of a predetermined condition in the circuit. The mechanism is movable between a tripped position, a reset position, an off position, and an on position.
In one exemplary embodiment, spacers are operatively positioned between movable members, and protrusions are operatively formed on the enclosure. The spacers and protrusions serve to widen the stances of the operating mechanism for force distribution purposes, and also to minimize friction between movable components.